Evolutionary drift. The active sequence space (open circles) was obtained by the MDS analysis of the human GPCR set. Human receptors from the SO and PEP sub-families are indicated by red and green circles, respectively. The supplementary sequences correspond to SO receptors from N. vectensis (closed diamonds), C. elegans (open triangles), C. intestinalis (crosses) and D. melanogaster (closed squares). The active and supplementary sequences are projected onto the plane defined by the first two components of the active space. Plot drawn with the mmds.2D.plot function.
Pelé et al. BMC Bioinformatics 2012 13:133 doi:10.1186/1471-2105-13-133